P163/235 Thrombolysis and collateral flow in interhospital transfer for thrombectomy: implications for recanalization and infarct growth

Introduction

Collateral flow may mediate the effect between thrombolysis and macro and microvascular reperfusion in patients with large-vessel occlusion (LVO) transferred for endovascular treatment (EVT).

Aim of Study

To investigate the interaction between thrombolysis and collateral flow in interhospital infarct growth and recanalization before EVT.

Methods

This was a cohort study of consecutive anterior circulation LVO transferred patients from a primary stroke center (PSC) to a single comprehensive stroke center (CSC). We included patients who underwent repeated CT scans, and the rate of ASPECTS decay (RAD) was defined as (ASPECTS PSC – ASPECTS CSC) divided by the hours elapsed between scans. Collateral score was assessed in the PSC single-phase CTA on a scale from 0 to 3.

Results

We included 264 transferred patients who underwent CT before EVT, of whom 91 (34.5%) received thrombolysis in PSC and 116 (43.9%) had good collaterals. RAD in each collateral score was not modified by bridging thrombolysis (mean, SD) [score 0: 1.49 (0.4) vs. 1.52 (1.1); score 1: 0.66 (0.7) vs. 0.70 (0.6); score 2: 0.33 (0.5) vs. 0.45 (0.6); score 3: 0.24 (0.4) vs. 0.23 (0.3)]. In patients with good collaterals, 7.9% of those without bridging thrombolysis recanalized before EVT, while 16.7% of patients with bridging thrombolysis recanalized. In patients with poor collaterals, recanalization was observed in 2.9% and 6.5% of patients, respectively.

Conclusion

Collateral flow and thrombolysis may have a positive interaction in macrovascular recanalization. However, thrombolysis does not appear to interfere with collateral-mediated infarct growth

Disclosure of Interest

Nothing to disclose